Detail is https://github.com/rbenv/rbenv
$ brew install rbenv ruby-build gibo
$ rbenv install 2.5.3
$ rbenv global 2.5.3
$ rbenv rehash
$ gem install rails
#=> the rails version is same boilerplate one
$ rails new project_name --template="https://raw.githubusercontent.com/Islands5/rails_template_source/master/template.rb" --database=postgresql --skip-action-mailer --skip-action-cable --skip-sprockets --skip-coffee --skip-javascript --skip-turbolinks --skip-test --skip-system-test --skip-bundle
$ cd project_name
NOTE: if you wanna use monogdb, remove --database option
vanila webpack :)